Elongated percussive rock drilling element
AssigneeSandvik AB
InventorsJohan Lindén, Lars-Gunnar Lundell
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Abstract
The present invention relates to a martensitic, corrosion resistant steel for rock drilling with properties which is adjusted essentially with regard to resistance against corrosion fatigue. This has been obtained in that an elongated element for percussive rock drilling which includes at least a thread and a flush channel has been made with corrosion resistant steel having a mainly martensitic structure.
Claims8
An elongated percussive rock drilling element including at least a thread portion and flush channel, at least the thread portion is made of a corrosion resistant steel having a martensite content of >50 wt-% but <100 wt-% and that the steel has a composition comprising:
- 0.1 wt-%≦C+N≦0.8 wt-% and Cr≧11 wt-%.
An elongated percussive rock drilling element including at least a thread portion and flush channel, at least the thread portion is made of a corrosion resistant steel having a martensite content of >75 wt-% but ≦98 wt-% and that the steel has a composition comprising:
- 0.1 wt-%≦C+N≦0.8 wt-% and Cr≧11 wt-%.
An elongated percussive rock drilling element including at least a thread portion and flush channel, at least the thread portion is made of a corrosion resistant steel having a martensite content of >50 wt-% but <100 wt-% and that the steel has a composition comprising:
- 0.1 wt-%≦C+N≦0.8 wt-% and Cr≧10 wt-%.
Dependencies are inferred from the claim text.